On a hillside in the Japanese town of Hitachi-ota, a glass-walled structure glows after dark, powered not by solar panels or wind turbines but by 1,500 wooden boxes filled with soil and compost. The lab, named Ku-An, is the work of Satoshi Nakagawa, a 72-year-old designer and engineer who has spent years convincing sceptics that everyday materials can yield a trickle of electricity.
Nakagawa, chief executive of the design firm Tripod Design, calls his approach "micropower collection" (MPC). It borrows from the voltaic pile, the first battery to produce a continuous current, invented by Alessandro Volta in 1799. By inserting electrodes of zinc and copper into moist, ion-rich substances—soil, water, food waste, even wine or French bread—Nakagawa collects small but steady electrical currents.
The technology is not about replacing the grid. Nakagawa sees it as a way for people to generate their own power from what lies beneath their feet. "As the population moves toward 10 billion, energy issues will become just as critical as food issues," he told AFP. "Even if it's just a small contribution, I want people to be able to produce their own electricity using the soil around them."
From rice cookers to firefly-like lights
Next to Ku-An stands Lu-An, opened last year, which uses more than 2,000 plastic cylinders of soil and compost to generate 100 watts—enough to run a rice cooker or other small appliances. Nakagawa has also built prototype "stand-alone nodes": bollard-like devices powered by soil that can communicate with satellites, potentially useful for remote monitoring.
He envisions applications in places without reliable power, including after natural disasters. Low-power sensors could detect pest damage on farmland, rising river levels, landslides, or even act as burglar alarms. Once installed, the system produces no carbon dioxide and, unlike solar or wind, is not dependent on weather.
For art installations, Nakagawa has created flexible rods that, when stuck into the ground, glow at the tips like fireflies in tall grass—a poetic demonstration of what he calls "micro power."
Engineers praise beauty, question practicality
Professional engineers acknowledge the appeal but are cautious about the output. Masayuki Nakao, professor emeritus of engineering at the University of Tokyo, who has known Nakagawa for years, says the system's power is "significantly inferior compared with regular batteries or car batteries." Yet he adds: "What is notable about Mr Nakagawa's works is that the light that he creates has the power to move our emotions. People are moved by it when they see the lights. They are beautiful."
Nakagawa shrugs off the criticism. "I say it's micro power, so we have to think about what micro power can do," he says. He believes engineers should design products that make the most of small, local energy sources rather than always reaching for larger ones.
The idea resonates beyond Japan. In Europe, where solar power set a record share of EU electricity in June, the search for diverse, decentralised energy solutions is ongoing. While MPC is unlikely to rival wind or solar on a utility scale, it offers a complementary niche—especially for off-grid sensors and rural applications, much like the growth of solar in Portugal shows how smaller sources can add up.
Nakagawa's work also invites reflection on energy consumption. In a world of rising electricity costs, as seen in Spain's inflation driven by fuel and power prices, the idea of drawing a few watts from the ground is a reminder that energy can be local, humble, and even beautiful.
Whether micropower collection becomes a practical tool or remains an artistic provocation, Nakagawa has already achieved one goal: getting people to think differently about where electricity comes from.
